# 集合定义 {} 或者 set()
a = {1,2,3}
b = {2,3,4}

# 交集
print(a.intersection(b))
print(a&b)

# 并集
print(a.union(b))
print(a|b)

# 差集
print(a.difference(b))
print(a-b)

# 对称差集
print(a.symmetric_difference(b))
print(a^b)

c = {1,2,3,4}
d = {2,3}

# 子集
print(d.issubset(c))
print(d<c)

# 父集
print(c.issuperset(d))
print(c>d)

　输出

{2, 3}
{2, 3}
{1, 2, 3, 4}
{1, 2, 3, 4}
{1}
{1}
{1, 4}
{1, 4}
True
True
True
True

集合没有 “+” 运算符